Comb filter issues on Toshiba CRT

[CRTguy]

I have a Toshiba CF27C40 from '94 and when I watch content over composite on it, the dot crawl on edges is really noticeable and especially bad when an object is in motion. There is an inductor and a pot for the the comb filter and I have adjusted those as best as I can but the dot crawl is still pretty bad. I picked up another of this same model of TV 2 years ago and that set had an excellent picture over composite when no noticeable dot crawl at all. I got rid of that set because it had a bunch of other issues that I couldn't fix. This is also the same model set that I had growing up for 15 years so that is another reason why I know why this model of TV has a good comb filter.

I have the service manual and am in the process of getting some test equipment but in general, what are the most common causes of comb filter issues? Is it most likely to be something in the video circuit? Could it be a bad component in the power circuit?

[zeno]

Comb filters came out apx 1978 on Magnavox. In all the years since
then I never had to repair or adj one. At that probably change all
the electrolytic caps in that part of the circuit. Beyond that post
just the part of schematic with it. Someone else may have ideas.

Comb filters were unsung heroes of TV. You could demo one beside a non combed set & instantly up sell the set from $50 - $100.

73 Zeno
LFOD !